//console 控制台
//console.log(123);
//console.info(123);
//console.warn(123);
//console.error(123);
console.time('FOR-LOOP');
var sum=0;
for(var i=0;i<1000;i++){
   sum += i;
}
console.timeEnd('FOR-LOOP');

console.time('WHILE-LOOP');
var i=0;
var sum2 = 0;
while(i<1000){
  sum2+=i;
  i++;
}
console.timeEnd('WHILE-LOOP');